Annotations have been widely used in conventional articles, books and publications to provide interpretations (or comments) to the abbreviations, terms, concepts and persons contained in the articles, books and publications, to provide semantic information so that the readers can better understand the authors' thoughts and avoid ambiguities.
Since recent years, with the continuous development of the computer technology and network technology, more and more electronic publications have gradually constituted the way in which people read and browse to acquire knowledge. In the digitized electronic documents processing field, the applications of annotations have been further developed, and various contents and forms of annotations have occurred. Especially, with the popularization of markup languages such as HTML, XML etc. on the Internet, the annotations for electronic documents are no longer limited to the textual interpretations to abbreviations and terms, but also include: the web pages (of companies or individuals) containing related contents, network links such as hypertext links, and multimedia information etc.
For example, U.S. Pat. No. 5,146,552 entitled “Method For Associating Annotation With Electronically Published Material” by Elie Cassorla et al., disclosed a method for annotating online electronic book and a method for creating annotations and bookmarks in an electronic book, the contents of which are incorporated herein for reference in its entirety.
In electronic document annotation techniques of the prior art, no matter whether in the mode that annotation contents are embedded in an electronic document or in the mode that annotation contents are separated with an electronic document, the electronic document and the annotation contents thereof are recorded and stored in one to one correspondence, and both are delivered to readers for browsing. Consequently, there arises the problem that the same annotation contents are recorded and transmitted repetitively (redundantly) due to its occurring in multiple documents or even at multiple locations in the same document.